Logsearch: make ingestor update serial
Logsearch: make ingestor update serial

Update ingestor jobs zone-by-zone. But because these are 2 jobs
(because they have different property value - queue IP. We want
ingestors to process messages in the specific zone only to limit
cross-zone traffic), add serial: true to both of them.

jimconner/paas-cf,alphagov/paas-cf,jimconner/paas-cf,alphagov/paas-cf,alphagov/paas-cf,alphagov/paas-cf,jimconner/paas-cf,jimconner/paas-cf,alphagov/paas-cf,jimconner/paas-cf,alphagov/paas-cf,jimconner/paas-cf,alphagov/paas-cf,alphagov/paas-cf,jimconner/paas-cf